Currently, many telecommunication networks send and receive information as optical signals. Such networks can provide significantly greater bandwidth than their electrical wire counterparts. One reason for this is that a single optical fiber can carry multiple (e.g., 80 or more) signals on different wavelength channels simultaneously. In practice, such networks are highly dynamic and power in any given channel may fluctuate relative to other channels because of, for example, wavelength drift in network components, channel add/drops, and path reconfigurations. Thus it is often necessary to variably attenuate the intensity of a given optical signal in one or more channels. For example, this may be necessary to minimize channel cross-talk caused by nonlinear interactions between different channels.